diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/rust/regex-automata/src/util/prefilter/memmem.rs | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/regex-automata/src/util/prefilter/memmem.rs')
-rw-r--r-- | third_party/rust/regex-automata/src/util/prefilter/memmem.rs | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/third_party/rust/regex-automata/src/util/prefilter/memmem.rs b/third_party/rust/regex-automata/src/util/prefilter/memmem.rs new file mode 100644 index 0000000000..deea17bd9d --- /dev/null +++ b/third_party/rust/regex-automata/src/util/prefilter/memmem.rs @@ -0,0 +1,88 @@ +use crate::util::{ + prefilter::PrefilterI, + search::{MatchKind, Span}, +}; + +#[derive(Clone, Debug)] +pub(crate) struct Memmem { + #[cfg(not(all(feature = "std", feature = "perf-literal-substring")))] + _unused: (), + #[cfg(all(feature = "std", feature = "perf-literal-substring"))] + finder: memchr::memmem::Finder<'static>, +} + +impl Memmem { + pub(crate) fn new<B: AsRef<[u8]>>( + _kind: MatchKind, + needles: &[B], + ) -> Option<Memmem> { + #[cfg(not(all(feature = "std", feature = "perf-literal-substring")))] + { + None + } + #[cfg(all(feature = "std", feature = "perf-literal-substring"))] + { + if needles.len() != 1 { + return None; + } + let needle = needles[0].as_ref(); + let finder = memchr::memmem::Finder::new(needle).into_owned(); + Some(Memmem { finder }) + } + } +} + +impl PrefilterI for Memmem { + fn find(&self, haystack: &[u8], span: Span) -> Option<Span> { + #[cfg(not(all(feature = "std", feature = "perf-literal-substring")))] + { + unreachable!() + } + #[cfg(all(feature = "std", feature = "perf-literal-substring"))] + { + self.finder.find(&haystack[span]).map(|i| { + let start = span.start + i; + let end = start + self.finder.needle().len(); + Span { start, end } + }) + } + } + + fn prefix(&self, haystack: &[u8], span: Span) -> Option<Span> { + #[cfg(not(all(feature = "std", feature = "perf-literal-substring")))] + { + unreachable!() + } + #[cfg(all(feature = "std", feature = "perf-literal-substring"))] + { + let needle = self.finder.needle(); + if haystack[span].starts_with(needle) { + Some(Span { end: span.start + needle.len(), ..span }) + } else { + None + } + } + } + + fn memory_usage(&self) -> usize { + #[cfg(not(all(feature = "std", feature = "perf-literal-substring")))] + { + unreachable!() + } + #[cfg(all(feature = "std", feature = "perf-literal-substring"))] + { + self.finder.needle().len() + } + } + + fn is_fast(&self) -> bool { + #[cfg(not(all(feature = "std", feature = "perf-literal-substring")))] + { + unreachable!() + } + #[cfg(all(feature = "std", feature = "perf-literal-substring"))] + { + true + } + } +} |